Power transmission



'Aug. 27," 1940, w. T. DUNN POWER TRANSMISSION Original Filed July 15,1935,

n l M p .H 0" fl m a rim Lflm m 0 5, i fa; a 22 7 Q 2 2 4 46 My 1442.112Tzw BY M fin m A TTORNE Patented Aug. 27, 1940 POWER TRANSIVHSSION'William T. Dunn, Detroit, Micln, assignor Chrysler Corporation, HighlandPark, Mich., a corporation of Delaware Original application July 15,1935, Serial No. 31,321. Divided and this'application February 9, 1939,Serial No. 255,365

' Claims. (01. 192-48) This invention relates to power transmission andrefers more particularly to improvements in speed ratio changingmechanism especially adapted for use in driving motor vehicles.

This application is a division of my copending application SerialNo.31,321, filed July 15, 1935.

-One' object of my invention is to provide an improved speed ratiochanging mechanism preferably providing an overdrive, or a speed greaterthan 1 to- 1 between driving and driven shafts in the transmission ofpower from the engine to the vehicle ground wheels,

More particularly, further objects of my invention are to provide amechanism of the charof long life, quietness of operation, automaticresponse to the speed of vehicle travel, and relatively low cost.

Another object of my invention is to provide an ing and driven shaftsincorporating releasable means in the normal direct drive between theshafts and wherein the releasable means provide a two-way direct driveprior to the synchronizing action ofthe members of the automatic clutch;also releasable means for the normal direct drive which may pass througha clutch, preferably of the roller type, to provide a two-way directdrive independently of the automatic clutch which controls the overdrivegear train.

A further object of my invention is to provide an improved arrangementof driving means providing the overdrive gear .train, this gear trainbeing controlled by an automatic clutch of the centrifugal forceoperated type, in combination with a releasable direct driving meansresponsive in its control to operation of the automatic clutch forpermitting the driven shaft to overrun the drivingshaft in synchronizingthe rotational speeds of the automatic clutch structures.

A further object of my invention is to provide an improved control forclutching means, which may be of the automatic centrifugal force type,for controlling'the drive through a change speed 3 gear train, thiscontrolling means being so arranged that operation of the clutchingmeans toward clutching engagement is prevented until relative movementtakes place between the driving and driven shafts. This control ispreferably arranged to prevent operation of the clutching means eventhough theclutching means is subjected to conditions otherwise tendingto effect movement of the clutching means toward clutch acter aforesaidhaving improved characteristics automatic overdrive mechanism betweendrivengagement, especially where the clutching means includes acentrifugal force operated clutching element. Such arrangement undesiredwear of the clutching means and noises incident to the ratcheting effectof certain types of clutching means and has other advantages which willpresently be more apparent.

Further features of my invention reside in an improved direct drivingclutch for controlling an overdrive; also an improved direct drivingclutch having rollers adapted to provide a two-way prevents direct driveconnection and a control therefor Y operable by movement of thecentrifugal force actuated element of the overdrive control clutch.

A further object of my invention is to provide an] automatic overdriveadapted to function in controlling the-drive with a minimum of manualcontrol necessary, my invention including a manual1y operated control onthe automatic clutch, which control may be dispensed with if desired.

Further objects and advantages of my invention will be,more apparentfrom the following detailed description of one illustrative 'embodi-'ment of my invention, reference being had to the accompanying drawing,in which:

' Fig. 1' is a sectional elevational View of my overdriving mechanism. V

Fig. 2 is a transverse sectional elevational view taken approximately asindicated by the line 2-2 of Fig. 1.

Fig. 3 is a sectional elevational view taken approximately as indicatedby the line 2- -2 of Fig. 1.

Fig. 4 is a detail sectional elevational view taken as indicated by theline 4-4 of Fig. 1.

Fig. 5 is a view corresponding to Fig. 4 but illustrating a modifiedform of my direct driving. control clutch.

Fig. 6 is a detail plan view of the Fig. 5 clutch looking down on theclutch rollers and cage.

Referring to the drawing,'I have illustrated my overdriving mechanismoperating between a power driving shaft I 0 and a driven shaft ll. Thesetwo shafts may be arranged anywhere along the line of power,transmission between the usual engine and driving ground wheels of themotor vehicle and inasmuch as such partsare well known, I have notillustratedthem in my drawing. The shaft ID preferably receives itsdrive from the usual change speed transmission mechanism which may belocated in the casing l2 to the rear of which is located the casing l3for housing the overdrive mechanism.

Shaft I0 is suitably rotatablyjournalled, one

bearing therefor being shown at l4 while shaft isrotatably journalled bybearings I5 and IS, the usual speedometer drive being taken from shaftII by the gearing I1 and I8 in a well known I manner.

The driven shaft is provided with an enlarged forward extension coaxialwith the aligned axes .of shafts I8 and II and surrounding the rear end-with a plurality of circumferentially spaced planetarygears 21 mountedon axles 28 connected by the ring-like carriers 29 and 38. Thesecarriers may also be connected intermediate a pair of the planetarygears by suitable spacing structures 30' and the carrier 38 is providedwith -a rearwardly extending driving member in the form of a cylindricalportion 3| thereof having'a plurality of circumferentially spaced slots32 adapted for clutching engagement with the centrifugal force, operatedclutching element 33 as will be presently more apparent.

The planetary gears 21 also mesh with a sun gear 34 carried by a sleeve35 freely surrounding shaft i8 and non-rotatably secured by teeth 36with a bracket 31 secured to the stationary casing I2. I

The rear end of shaft I8 is provided with splined teeth 38 for drivinglyengaging a cage 39 adapted to carry the clutching element or pawl 33whereby the latter is rotated with the cage and capable of radialmovement relative thereto in the cage guides 4|. The pawl 33 has: aninwardly extending yoked portion 42 surrounding shaft l8 and terminatingin a .diametrically opposite end portion 43 adapted to house a spring 44acting between shaft l8 and an adjustable abutment screw plug 45threaded in the outerend of the end portion 43. The spring 44 acts toyieldingly urge the pawl 33 into the position illustrated in Fig. 2, theshaft l8 serving to limit the movement of the pawl in this directionwhich is the disengaged position of the pawl with respect to itsclutching position with one of the slots 32.

The pawl '33 is adapted for clutching engagement with a slot 32 when therotational speeds of the pawl and slot are substantially synchronizedand in order to facilitate this synchronizing action at the time ofclutching engagement of pawl 33,- I preferably provide a releasabletwoway clutch between the driving and. driven shafts to permit at leastthe necessary relatively small amount of relative overrunning movementbe-- tween shafts l8 and H at the time of clutching engagement. Areleasable vclutch in the .form of a roller clutch will be satisfactoryfor this purpose in order to permit the driven shaft to togethermaintained in their properly spaced relationship by a roller cage orspacer ring 48.

The spacer ring 48 is provided with a forwardly extending projectingportion in the form of forked extensions. and 58, the clutching element33 closely fitting between these forked extensions when projectedoutwardly into clutching engagement with one of the slots 32 asillustrated in Fig. 3. These extensions 48 and 58 provide a latchingmeans or releasable blocking means for the clutching element 33 as willbe'presently more apparent. e

The arrangement is such that when the centrifugal clutching element 33is in its disengaged or fully retracted position illustrated in Fig. 2the rollers 41 together with cage 48 are free to move rotatively ineither direction as indicated by the dotted line position of a typicalroller in Fig. 4 as when the cam 46 drives the cylindrical portion 22 orwhen the cylindrical portion drives the cam whereby the direct two-Waydrive may be transmitted between shafts l8 and II. In order to permitthis relatively small amount of relative movement between cam 46 andcylindrical portion 22 in either direction, the cen trifugal clutchingelement 33 is formed with a pair of rearwardly opening grooves 5|, thesegrooves extending toward each other at the rear face of element 33 inrotational alignment with cage projections 49 and 58 so that whenelement 33 is retracted as in Fig. 2,- one or the other of blockingprojections 49 and 58 may enter a groove 5| depending on the directionof movement of rollers 41 in providing a drive relatively between shaftsl8 and II in either direction.

The lowerfaces of grooves 5| are preferably.

chamfered at 52 to assist in moving cage 48 to its neutral position atwhich time the rollers 41 are at the center of the cams of the cammember 46 vso that clutch portions 46 and 22 may freely ing element 33to move outwardly for engagement in one of the slots 32, I have providedthe following mechanism. One of the splines 38, such as the spline 38 iselongated forwardly to slidably accommodate a shifter rod 53 which isbent in a direction outwardly of shaft l8 ati 54 to position this bentend in an opening of a collar 56 slidable on shaft ID. The collar 56rotates.

with rod 53 and shaft I8 and for sliding the col lar and rod, the collaris engaged by the forked end 56 of a lever 51 which is pivotallysupported at 58 and adapted for manual manipulation at a convenientpoint through a suitable linkage such as the Bowden wire mechanism 59.The rear end of shifter rod 53 is provided with an enlarged key portion68 adapted for selective manual position forwardly into'a suitablerecess 6| formed in the cage 39 or else rearwardly in the plane of yoke42 so as to occupy the space between this yoke and shaft I8 and therebyserve as a stop holding clutching element 33 in the Fig. v2 position andpreventing its outward movement. In Fig. 1 the key or stop 68 isillustrated in its forwardly adjustable position whereby the' automaticclutch mayoperate at or above its critical speed of rotation ofclutching element 33 and if desired this manual control may be dis p sedwith. In certain instances it is desirable to render the automaticoverdrive inoperative and in such instances the motor vehicle driver maymanipulate the Bowden wire 59 to move the stop 60 rearwardly and therebyprevent any outward movement of clutching element 33. Under the latterconditions it will be understood that a g with the manually controlledstop 60 in its forward or inoperative position, it will be apparent thata two-way direct drive is provided through .shafts'lll and H, therollers. 41 being adapted to rotatably move into the approximate dottedline positions of Fig. 4 for the respective opposite directions of drivethrough the shafts l0 and II. v

When the motor vehicle is driven at or above a predetermined speeddepending on the strength and setting of spring 44 and the effectivemass of clutching element 33 tending to move outwardly by centrifugalforce, the clutch element 33 will be urged outwardly by centrifugalforce acting thereon. At this time it will be understood that normally adirect forward drive will be taking place'between shafts i0 and l I, therollers 41 and cage 48 moving slightly in the direction opposite to thedirection of rotation of shaft l0 and cam 46 for positioning the cageprojection 50 into the adjacent groove 5| of the clutching element.Therefore, whenthe critical speed for.

clutching element 33 has been passed, whenever the motor vehicle driverreleases the usual acceleratqr pedal whereby driven shaft ll tends todrive the driving shaft 10, the cylindrical clutch portion 22 willendeavor to overrun the eam portion 46 causing the rollers 41 to movetoward their other-dotted'line DOSiti'OlbOf Fig. 4

and cage 48 will, of course, move with the rollers to disengage cageprojection 5! from groove 5| whereupon clutching element 33 willimmediately be projected outwardly with the outer cammed i faceof theclutching element rubbing on the inner cylindrical face of carrierextension 3|. During such time the clutching element 33 will nothavetime to register with one of the slots 32 until these parts aresubstantially syiifih onized in their rbtational speeds, the initialijutward .movement of clutching element 33 prior to synchronizationtaking up the clearance between the clutching element and carrierportion 3! and thereby moving the clutching element sufficiently tobringthe chamfers 52 just outwardly beyond engagement with the pageextensions and 5D. In this manner the cage 4Bwill be held in its neutralposition .just as soon as clutching element '33 has its initial outwardmovement, it being apparent that shaft I ll andgclutching .portion 22may freely overrun shaft Ill and cam 46 for the purpose of synchronizingthe rotationalspeeds of slots32 and clutching element 33. The

tion of drive'takes place between the driving and rotational speed ofthe clutching element will quickly: drop to approximately that of slots32 whereupon the clutching element will have a further outward movementin entering a slot.32 and. thereby provide [a positive clutchingengage-- ment between thclut'ching element and carrier 30. In thismanner the driving shaft I0 is positively drivingly coupled for atwo-way drive -for driving the driven shaft faster than the drivingshaft, such drive passing from shaft III through the (cage 39 thencethrough the clutchand causing the internal gear 26 and cylindricaldriving member 25 to rotate along with the driven shaft- II at afaster'speed' than driving shaft l0 depending on the value of theplanetary gear train as will be presently understood. During thisoverdriving action the cage 48 will be held in its central or'neutralposition withr'espect to the cams of the cam member 46. The purpose ofthe chamfers 52 is toassist in moving the c ing element 33 to thecarrier 30,.the planetary gears 21 rolling around the fixed sun gear 3Q.

cage 48 to its neutral positionduring the aforesaid initialoutwardmovementof clutching element 33. r

The drive will continue as an overdrive until such time that the speedof motor vehicle travel is sufficiently reduced to urge the clutchingelement 33 inwardly by reason of spring 44 acting on the portion 43 ofthe clutching element. At'

such time the clutching ,element is retracted so that it is disengagedfrom a slot 32, the clutching element. 33 moving inwardly to again aligngrooves 5| with the'ends of cage extensions 49 and 53 at which time theoriginal drive may take place in direct ratio between shafts l0 and IIineither direction, one or the other of cage extensions 49 or 50 movinginto one of the grooves 5! in cammin'g rollers 41.

While the centrifugal force acting on rollers 41 will ordinarily besufficient to urge the rollers outwardly against cylindrical portion22so that the rollers will quickly respond to the aforesaid tendency ofshaft I l to overrun shaft I0 for shifting cage 48, Imay also assist inthe out-' ward positioning of rollers 41 particularly at relatively slowspeeds by the addition of a spring wire 62 of substantially circularform fitting in a groove 63 in the face, of car'n member 46, this spring62 yieldingly urging the -rollers 41 outwardly. y a

It will be noted that I have provided means for controlling theoperation of the automatic; clutch when'the car is being driven.directly through the overrunning clutch, such controlling means actingto prevent the clutch pawl 33 from moving outwardly under the, influenceof centrifugal force, even though the speed of rotation of the pawl issuch as to otherwise cause the pawl tg pe projected outwardly. Thiscontrol will beqgrli'aintained on the pawl, above the criti-j realspeed, until such time as the car tends to drive the engine, resultingin release of the aforesaid latching means or projection 50 from groove5i, whereupon the pawl is free to move outwardly for engagement with oneof the .;slots 32 when the members of theautomatic clutch are synchronized as aforesaid. 'In this manner I have prevented, during thedirect' drive above the critical speed of "the automaticclutchdratcheting of the pawl together with inherent-noise and wearofthe clutch parts. Such arrangement, I V

therefore, automatically renders the automatic clutch inoperative, even"aboveits critical speed, until such time as a reversal of the normaldirec tral position in either direction for obtaining the two-way drivebetween the driving and driven shafts, I have illustrated a modifiedarrangement of the-two-way releasable driving clutch in Figs.

' said member 22 in Fig. 1.

5 and 6. It will be understood that in these figures the clutchillustrated may be readily substituted for the corresponding clutchshown and described in the previous embodimentof my invention and forthe most part the operation of this clutch is the same in connectionwith the overdriving mechanism as previously recited.

In Figs. 5 and 6 a pair of axially spaced rollers l! and 41 areassociated with each of the cam faces of the cam member 46 the outercylindrical clutching portion 22 corresponding to the afore-' The cageus is built around these rollers sothat it will move as afore. said withthe pairs of rollers maintained in their properly spaced relationship.In Figs. 5 and 6 the rollers are illustrated in their neutral positionsand on rotational movement of cage 38 in either direction one of therollers 47 or 41 is required to move only a relatively small amount inlooking up between the clutching portions 28 andZZ it not being requiredthatany roller need .pass through its neutral position from one lock upposition to the other lock up position for the two-way drive as in thecase of ,the clutching device illustrated in Fig. 4. This" arrangementwill and arranged as to respectively automatically drivingly connectsaid clutching structures when said driving shaft tends to rotate fasterthan said driven shaft and when the driven shaft tends to rotate fasterthan the driving shaft.

2. In a motor vehicle drive, a driving shaft, a driven shaft alignedtherewith, two-way clutch means releasably coupling said shafts for adirect two-waydrive therebetween, said clutch including a pair ofmembers onedisposed concentrically within the other, one ofsaid membershaving a plurality of cam faces and the other having a cylindricalportion, and a pair of rollers engaging each of said cam faces and saidcylindrical portion, the rollers of each pair having their axesrelatively spaced, in the direction of rotation of said shafts.

3.;Ina clutch control for drivingly connecting .driving and drivenshafts, a first clutch structure adapted to be driven from one of saidshafts, a

second clutch structure adapted to be driven from the other of saidshafts and being movable relatively to the first clutch structure forpositive clutching engagement therewith, a roller clutch I comprisinginner and outer clutching members respectively adapted for drivingconnection with said shafts and clutching rollers between saidclutchingmembers, and a cage for said rollers having a blocking portion disposedin the path of movement of said second clutch structure and soconstructed and arranged as to obstruct move-- ment thereof.

4. In a clutch control for drivingly connecting driving and drivenshafts, afirst clutch structure adapted to be driven from one of saidshafts, a second clutch structure adapted to be driven from theother ofsaid shafts and being movable relatively to the first clutch structurefor positive clutching engagement therewith, a roller clutch comprisinginner and outer clutching 'members respectively adapted for drivingconnection with said shafts and clutching rollers between said clutchingmembers'and a cage for said rollers having a blocking portion disposedin the path of movement of said second clutch structure and shafts toprovide a drive therebetween when the clutch structures are engaged, andcontrol means vfor releasably preventing relative movement of saidclutch structures relatively toward each other, said control meanscomprising a roller clutch operably disposed between said shafts andhaving a roller cage provided with a portion thereof obstructingmovement'of one of said clutch structures toward the other as long asthe driving shaft is rotating at least as fast as the driven shaft.

6. In a clutch control for drivingly connecting driving and drivenshafts, positively engageable clutching structures one movablerelative'to the other and respectively adapted for driving connectionwith said shafts, and a roller clutch operable to drivingly connect saidshafts and having a portion thereof provided with a blocking partengageable with one of said clutching structures to prevent movementthereof toward the other of said clutching structures. i

'7. In a clutch-control for drivingly connecting driving and drivenshafts, positively engageable clutch structures one movable toward theother and respectively adapted for driving connection with said shafts,a roller clutch comprising inner and outer clutch members respectivelyadapted for drive connection with said shafts and a roller cage having ablocker extension thereof engage able with said movable clutch structureto control movement thereof toward the other of said clutch structures.

8. In a clutchcontrol for drivingly connecting driving and drivenshafts, positively engageable 7 structure to control movement the'reoftoward the other of said clutch structures.

9. In a clutch control for drivingly connecting driving and drivenshafts, positively engageable clutching'structures one movable relativeto the other and respectively adapted for driving connection with saidshafts, and a roller clutch operable to drivingly connect said shafts,sai d' roller clutch comprising inner and outer,rollr clutch members, aclutch roller between said; clutch members, and a positioning member forsaid clutch roller, one of the members aforesaidhaving a blockerportion-adapted to control movement of said movable clutching structuretoward the other of said clutching structures. a

'10. In a clutch control for drivingly connecting driving and drivenshafts, positively engageable clutch structures one movable toward theother and respectively adapted for driving connection with said shafts,a. roller ciutc'h comprising inner and outer clutch members respectivelyadapted for drive connection with said shafts, a clutch rollercooperable between said clutch members, and a positioning member forsaid clutch roller, one of the members aforesaid having a blockerportion adapted to block movement of said movable clutch structureduring asynchronous rotation of said clutch Structures, said blockerportion being displaced relative to said movable' clutch structure toaccommodate movement of this clutch structure toward the other of saidclutch structures in response to approximate synchronous rotation ofsaidclutch structures.

WILLIAM 'r. DUNN.

